other way to solve this problem

[chenmocoder]

https://github.com/socketio/socket.io-redis or https://github.com/lklepner/socket.io-adapter-mongo can solve multi servers that use socket.io. use redis or mongo store socket.io's session.

[knoxcard]

I use socket.io-redis with a MariaDB+Redis tech stack, works great! You have to set it up right though ;-)